Research suggests, “Voice-controlled assistants by Amazon, Apple and Google could be hijacked by ultrasonic audio commands that humans cannot hear”.

it is reported that the assistants responded to commands broadcast at high frequencies that can be heard by dolphins but are inaudible to humans.

Google reported that the claims presented in the research is being investigated

Researchers in China set up a loudspeaker to broadcast voice commands that had been shifted into ultrasonic frequencies.

They said they were able to activate the voice – controlled assistant on arrange of Apple and Android devices and smart home speakers from several feet away.

And a US team was also able to activate the Amazon Echo smart speaker in the same way.

The Chinese researchers suggested an attacker could embed hidden ultrasonic commands in online videos, or broadcast them in public while near a victim.

In tests they were able to make calls, visit websites, take photographs and activate a phone’s airplane mode.However, the attack would not work on systems that had been trained to respond to only one person’s voice, which Google offers on its assistant.

Apple and Google both allow their “Wake Words” to be switched off so the assistants cannot be activated without permission.

According to report, a Google spokesman said, “we take user privacy and security very seriously at Google and we are reviewing the claims made.”

Dr Steven Murdoch, a cyber-security researcher at University College London said,” Even though the devices are not designed to handle ultrasound, if you put something just outside the range of human hearing, the assistant can still receive it so it’s certainly possible” .

"Mac OS X is like living in a farmhouse in the country with no locks, and Windows is living in a house with bars on the windows in the bad part of town." -- Charlie Miller